title: Illusory misidentifications and cortical hypometabolism in Parkinson's disease.
abstract: Idiopathic Parkinson's disease (PD) is associated with documented impairments in various visual functions. However, there have been only a limited number of studies that have reported on the brain regions responsible for impairment of visual recognition in PD. In our study, we evaluated the performance of PD patients and 24 healthy controls on the Poppelreuter-type overlapping figure identification test to investigate the impairment of visual recognition. We also measured the PD patients' resting cerebral glucose metabolism using (18) F-fluorodeoxyglucose positron emission tomography and investigated the relationship between the impairment of visual recognition and cortical hypometabolism. The PD patients had substantial and frequent illusory responses in the overlapping figure identification test, and their illusory misidentifications were correlated with hypometabolism in the visual cortices, including the right inferior temporal gyrus and the bilateral temporo-parieto-occipital junction. These findings suggest that PD patients have impaired visual recognition characterized by illusory misidentifications of visual stimuli, which could be attributed to dysfunction of the visual cortices.
authors.affiliation: Department of Behavioral Neurology. and Cognitive Neuroscience, Tohoku University Graduate School of Medicine, Sendai, Japan. t-ishioka@umin.ac.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Ishioka
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hirayama
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Hosokai
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takeda
authors.forename: Kyoko
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nishio
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Sawada
authors.forename: Shoki
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukuda
authors.forename: Yasuto
authors.initials: Y
authors.lastname: Itoyama
authors.forename: Etsuro
authors.initials: E
authors.lastname: Mori
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D021641:Recognition, Psychology / Q000502:physiology*; D014792:Visual Acuity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18